P7: Influence of neuroimplant materials on healthy cells of the CNS (K. Hattermann)

Implants in the brain can cause foreign body reactions of the surrounding healthy brain tissue, which is a long known problem for example of deep brain stimulation electrodes. These foreign body reactions include astrogliosis, glial scar formation, the loss of neurons and infiltration of immune cells affecting brain integrity and function on the one hand site and also impairing the implant function. However, cellular mechanisms of foreign body reactions of the brain parenchyma are poorly understood, and systemic approaches to improve the compatibility of implant materials are urgently needed.

Thus, we want to study the extent and mechanistics of the cellular reactions of brain parenchyma cells (neurons, astrocytes, oligodendrocytes, microglia) in response to the implant materials designed in the projects P1, P3 and P4 (permanent and degradable alloys, thin films, degradable barriers and coatings, as single devices and in combinations). These investigations will employ the individual cell populations of the brain, organotypic slice cultures and in vivo experiments in close cooperations with the medical projects P8, P9 and P10. Our aim is to characterize foreign body reactions regarding their intracellular signaling profile, their cellular effects, and their effects in the tissue in order to overcome the problems of foreign body reactions for the neuroimplant materials used in our study. Knowing the reactions on specific materials, we will be able to choose materials with faint adverse effects for further investigations at the end of the first funding period, and knowing the mechanisms of the reactions will enable us to supplement implant materials with bio active compounds that minimize local reactions and improve the functionality of the implants.